best antivirus for PC

Go to see my cousin cousin playing the game, I see the hand straight itch, opened the computer cousin and cousin, played games, but do not know why, we are very happy to play, play to play, when we are happy with my cousin’s computer black the screen, I do not know how, starting left several times are not used, the pen socket calls to check again, not the reason ah, his cousin came to watch the computer, that is computer virus, but he did not have time to install best antivirus for PC, the notes are installed the best antivirus for PC, the best antivirus for installed PC laptop is not like this, do not install best antivirus for PC computer is broken, or the best antivirus for PC believe.